an example of a good memo (i'm really into the essential clause):

Memo


To                    Denver Campus Faculty, Staff and Students

From                The Denver Campus Emergency Management Team

Date                 Dec. 22, 2011

Re                     Weather-Related Closure for the Denver Campus



Due to the heavy snowfall in the Denver metro area, the Denver Campus will be closed today, Thursday, Dec. 22, 2011. All personnel who are considered essential must make every effort to report to work, despite weather conditions. Please confirm directly with your immediate supervisor as to whether or not you would be considered essential personnel under such circumstances.



Thank you